1. Field of the Invention
The present invention is directed to an apparatus and method for applying liquid coatings to pellets in a flowing feed stream.
2. Description of Related Art
A continuing need has been identified for an apparatus which is capable of applying liquid coatings, such as liquid enzymes, to pelletized feed stock, in which the pellets are completely and evenly coated, and in which the apparatus is highly reliable, with low maintenance and low cost of ownership.
Enzymes are complex molecules which are naturally found in living organisms, and are used to speed up chemical reactions. In the animal feed industry, it has been found that, by adding a small amount of commercially available liquid enzyme to pelletized animal feed, complex structures within the feed that are not normally digested are, with the aid of the enzyme, made available for digestion. This allows for the reduction and/or elimination of certain feed additives, and also provides for higher nutrient yields.
It has also been found that lower cost corn/soy feed formulations, when combined with an appropriate enzyme addition, can provide similar nutritional value to more costly feed recipes which do not employ enzymes, and thus more economical primary feed ingredients can be used, resulting in lower production costs for the equivalent feed.
The enzyme phytase has also been successfully used in the broiler feed industry to liberate phosphorous normally not extracted through the digestive process. The use of phytase in the feed effects the reduction of phosphorous in the waste, thereby reducing potential environmental issues related to the disposal of that waste, and possible runoff into streams, lakes and tidal water systems.
Liquid enzyme formulations are readily available in concentrate form, and are normally diluted with water immediately prior to application. The apparatus and method of the present invention have been developed in order to achieve an accurate, highly repeatable means to apply liquid enzyme to pelletized animal feed, while reducing the overall dosing, and while achieving the desired minimal target activity within the pelletized product. This results in a minimized use of enzyme per quantity of feed pellets processed, and an attendant cost savings. The increased accuracy and high repeatability also provides the ability to formulate more economical feed recipes by being able to better predict and define the resulting nutrient value of the feed, such that it meets preset minimum nutrient value requirements for specific animals or specific ages of animals to be fed.